Linked Life Data

2446724

Source:http://linkedlifedata.com/resource/pubmed/id/2446724

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
1988-2-11
pubmed:abstractText
Biphasic contractions were obtained in guinea-pig papillary muscle by inducing partial depolarization in K+-rich solution (17 mM) in the presence of 0.3 microM isoproterenol. Mn2+ ions inhibited the two components of contraction in a similar way. Nifedipine and particularly Cd2+ ions specifically inhibited the second component of contraction. Isoproterenol and BAY K 8644 markedly increased the amplitude of the second component (P2) of contraction. Nevertheless, a moderate positive inotropic effect of isoproterenol was found on the first component (P1) of contraction when excitability was restored by 0.2 mM Ba instead of isoproterenol. Acetylcholine and hypoxia decreased the amplitude of the second component of contraction to a greater extent. In the presence of digoxin or Na+-free solution, P1 was strongly increased. When sarcoplasmic reticular function was hindered by 1mM caffeine or in the presence of Ca2+-free Sr2+ solution, digoxin always induced a negative inotropic effect on P2. Inversely in these conditions the transient positive inotropic effect of Na+-free solution was strongly reduced. These results are consistent with the hypothesis that the late component of contraction is triggered by the slow inward Ca2+ current and that the early component is due to Ca2+ release from the sarcoplasmic reticulum.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0008-4212
pubmed:author
pubmed:issnType
Print
pubmed:volume
65
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1832-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
Calcium channels and excitation-contraction coupling in cardiac cells. II. A pharmacological study of the biphasic contraction in guinea-pig papillary muscle.
pubmed:affiliation
Department of Physics, University of Calgary, Alta., Canada.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't